function cat (name,color){
    this.name = name;
    this.color = color;
}
cat.prototype = {
sayMiao (){
    console.log('喵喵');
}
}
Object.prototype.sayHello =function(){
    console.log('你好');
}
var xmm = new cat('陈喵喵','白色');
xmm.sayMiao();
console.log(xmm._proto_ == cat.prototype);
xmm.sayHello();
console.log(xmm.hasOwnProperty('name'));
xmm.hasOwnProperty('sayMiao')
console.log(xmm._proto_); // cat()
console.log(xmm._proto_._proto_); // Object()
console.log(xmm._proto_._proto_._proto_); // null
